It's very common question on SCN 
why dont you search carefully before posting new entry.
Anw OT in -ve => you have to input manually: assuming input in IT2010 or IT2002 (up to you), if +ve Time Schema should generate automatically basing on check in/out time.
You have to clear PCR and schema, so you can control by yourself by creating new pcrs to handle it.
The link below is useful for you:
Early or Late coming and generation OT by T555Z
Useful documents for Schema & PCR configuration
If you are very deeply understand link above, you will find solution soon 
Regards,
Woody